Study On The Nutrition Character Of The River With Dam

The eutrophication problem caused by retaining and accumulating nutrition in the river with dam is one of the current hot issues of the water pollution problems. Under the collaborative impact of anthropogenetic activities and climate change, the reach of Shanzi Dam of Aojiang River as a source of drinking water is changing the nutrient transmission by dam construction that had been revealed through "algae bloom". The large number of blue green algae multiplication has threatened people's safety by drinking water. So the research of the nutritional character of the reach of Shanzi Dam has important theoretical and practical significance.The objectives of this study are to identify the characteristics of the water nutrition salt, plankton and the phosphorus in the sediment through field monitoring and laboratory analysis simulation technology combining routes. The conclusions of this paper include as follow:(1) The reach of Shanzi Dam is monomictic with a stable thermal stratification in Spring-Summer-Autumn (March to November). In Winter (December to the following January and February)it produce a homogeneous body of water temperature, which directly affected the vertical distribution of the parameters of nutrition salt, dissolved oxygen, pH value .(2) The predominant phytoplankton in winter of the reach of Shanzi Dam is diatom andspring is diatom with blue green algae. The blue green algae is the absolute advantage species in Summer and blue green alga and Cryptomonas are the main phytoplankton in Fall. There is always an " algae bloom " in the late spring and early Autumn each year with the predominant phytoplankton Microcystis flos-aquae, who loves high temperature and has a strong competitive advantage .The main zooplankton species are protozoan and rotifer category and the number of protozoan is more than 50% of the total number of zooplankton.(3) The content of total phosphorus in the surface sediment in Spring of the reach of Shanzi Dam is range from 600 mg/kg to 1000mg/kg and the content gradually increase from the Riverine Zone to Transition Zone and Lacustrine Zone. The...